* convert_orig_to_bbd: make -strip-tendencies work with attributes

  At least with things like "q3+::inwork".
* data update (systematic fix for same street coordinates)

  Systematically checked all streets with the same names which were
  nearer than about 5 km.
* data update
* cgi-test.t: test case for same streets in multiple cityparts
* removed Strassen::MultiBezStr, the data file data/multi_bez_str

  ... and everything related
* cgihead2.t: no special handling necessary anymore, all URLs are HEADable